1. Field of the Invention
The present invention relates to a fiber optic array, and more particularly, to such an array which is used in an optical scanning device.
2. State of the Prior Art
It is known in the prior art to use an array of optical fibers in a print head which is used to record information on a light-sensitive recording medium. The fibers can be arranged with their output ends in a linear array extending in a direction transverse to the direction of movement of the recording medium, and a light source, such as a light-emitting diode or a diode laser, can be connected to each of the fibers at an input end. The light in each of the fibers is modulated in accordance with an information signal to produce a desired image. Focusing means can be used in front of each fiber to cause the light to be focused to a point on the recording medium. It is desirable for the arrays of optical fibers to have a high packing density, i.e., a high number of fibers per unit width of the array, in order to limit the amount of data buFfering needed to produce the output image. There is a problem, however, in using increasingly thinner fibers to increase the packing density. As the fibers are made thinner, handling and alignment of the fibers becomes more difficult, and the thinner fibers are more likely to break in the assembly process.
Another method of increasing the packing density of optical fiber arrays is to use multiple layers, or rows, of fibers, as shown, for example, in U.S. Pat. No. 4,389,655, to Baues. In the Baues patent, there is shown an optical device for non-impact recording in which the recording head includes a linear array of optical fibers. The recording head comprises an adjustment plate having a plurality of grooves therein, and an optical fiber is secured in each of the grooves to form a first row of fibers. A second row of fibers is arranged above the first row, and the fibers in the top row are offset relative to the fibers in the bottom row. The second row of fibers is also supported in grooves in a second adjustment plate, with the grooves of the second adjustment plate facing the grooves of the first adjustment plate. A problem with this arrangement is that it is very difficult to get the proper spacing between the rows of optical fibers. A further problem is that the array is limited to only two layers, and it is advantageous to have more than two layers in certain applications.